Cupola furnace plant having a shaker ladle



June 25, 1968 B. SCHIMMEL ET AL 3,389,898

CUPOLA FURNACE PLANT HAVING A SHAKER LADLE Filed Dec. 14, 1965 5 Sheets-Sheet 1 June 25. 1968 B. SCHIMMEL ET AL 3,389,898

CUPOLA FURNACE PLANT HAVING A SHAKER LADLE Filed Dec. 14. 1965 3 Sheets-Sheet 2 June 25, 1968 a. SCHIMMEL ET AL 3,389,898

CUPOLA FURNACE PLANT HAVING A SHAKER LADLE Filed Dec. 14, 1965 '5 Sheets-Sheet 3 Fig. 3

United States Patent Claims. Cl. 266-13) ABSTRACT OF THE DISCLOSURE Combination in a cupola furnace apparatus includes a furnace having a tapping outlet through which molten metal from the furnace is continuously discharged; a ladle; a shaking ladle-means mounting the ladle so as to be capable of displacement from a normal to a tipping position, the ladle having a cover plate in which there is a supply opening for admission of molten metal and an out let opening for pouring molten metal therefrom; a tapping spout, one end of which is located to receive metal from the tapping outlet of the furnace and in the other end ofwhich is a discharge orifice for feeding metal into the ladle, the supply opening in the ladle extending over an arc whose length is proportional to the angular displacement of the ladle in moving to and from its tipped position whereby metal can be charged into the ladle in all angular positions of the ladle, even when the ladle is in a tipping position in which molten metal is being poured from said outlet opening thereof.

Cupol furnace iron is treated in a so-called shaking ladle in orderto produce a high grade cast iron from iron produced in a cupola furnace from a low grade charge. For this purpose the shaking ladle is disposed in a horseshoe frame. The shaking movement of the ladle is obtained through the fact tha-t'frame and ladle perform a circular movement while however not turning about theii vertical axis. 7

In one known method of operation, the iron leaving the cupola furnace, which is continuously tapped, passes by way of a swivelling tapping spout, in succession into one of two shaking'ladles disposed in a horseshoe-shaped swivelling frame. As soon as one ladle has been filled with the quantity of iron to undergo metallurgical treatment, the tapping spout is swung over'to the second shaking ladle to continue tapping without interruption. While the first ladle is being filled, the metallurgical treatment of the contents of this ladle'is effected. On completion of such treatment, the refined iron canbe emptied out by tipping the shaking ladle in the horseshoe-shaped swivelling frame, or in a tipping stand, into casting vessels, and after the tapping spout has been swung over again the shaking ladle is refilled with cupola furnace iron. This cycle is repeated alternately with the two shaking ladles.

Apart from the fact that two shaking ladles must be allocated to each cupola furnace, this method of working has the disadvantage that, because of the intermittent emptying of the shaking ladles into the casting vessels, temperature losses in the iron, corresponding to the total pouring time, cannot be avoided. If it be assumed that the contents of the shaking ladle amount to three tons and discharge is to be effected into casting vessels, each of which has a capacity of 600 kg, five pouring operations with corresponding intervals of time for the transport of the casting vessels to the casting station are necessary. The time required to carry out this operation can be estimated to be about 20 minutes, so that if the starting temperature is 1,480 C., the temperature of the iron in the fifth casting vessel after 20 minutes would be only 1,400-

3,389,898 Patented June 25, 1968 1,42( C. With falling temperature of the iron however, the proportion of waste increases, apart from the fact that castings of varying quality are obtained because of the different pouring temperatures. v

If the iron melted in a continuously operated cupola furnace is poured without the use of shaking ladles, the tapped iron first passes into a forehearth which is tippable, from which the casting vessels are filled as required. Through the continuous arrival of hot iron the temperature in the-forehearth, and therefore also in the casting vessels is kept substantially constant, and thus uniform quality of the casting is achieved.

Themain object of this invention is to eliminate the disadvantages entailed by the alternate use of two shaking ladles coupled with the not inconsiderable temperature drop, and the provision of an apparatus for receiving and metallurgically treating the pig iron continuously leaving the cupola furnace, said apparatus permitting the pouring of a cast iron independent of the cupola furnace charge and with a substantially constant pouring temperature. We have overcome this problem, according to the invention by operating the cupola furnace with only a single shaking ladle mounted in a swivelling frame and capable of being tipped, in such a manner that the ladle is designed for continuous entry and discharge of the iron and supplies the foundry with a cast iron of the particular nature required and at a uniform temperature. The decisive feature is that the tapped iron continuously flows into the shaking ladle and that before the iron is poured into the casting vessels, the usual desulphurisation and alloying treatment can be carried out inside the ladle.

Apparatus according to the invention consists of a continuously tapped cupola furnace associated with a single shaking ladle mounted in a swivelling frame having a tipping device to enable the ladle to be tipped. The shaking ladle incorporates a cover plate, in which is an inlet opening corresponding to the arc of the tipping angle, the opening being covered by a canopy forming part of or carried by a tapping spout. In order to permit undisturbed removal of the slag from the shaking ladle and also to replace the latter, the tapping spout preferably consist of two parts, of which the front part has a receiving well at its rear end. Since the outlet orifice in the front part of the spout is always situated over the inlet aperture of the shaking ladle, whatever the position into which the latter is tipped, even during the filling of a casting vessel or during the tipping of the shaking ladle for the purpose of removing slag, unhindered admission of iron is always ensured.

An apparatus in accordance with one embodiment of the invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a vertical section through an apparatus according to the invention.

- FIGURE 2 is a viewsimilar to that of FIGURE 1, but

showing the shaking ladle in the pouring position and FIGURE 3 is a plan view of the apparatus of FIG- URES 1 and 2, shown diagrammatically.

The apparatus of this invention consists of a shaking ladle 1, which is mounted for tipping movements by means of two trunnion type journals 12 in a horse-shoe-shaped swivelling frame 2. The swivelling frame 2 is supported at three points, 2 1, 22, 23 (FIGURE 3), on hearing blocks -P, P, each block having an eccentric crank T, by which it is connected to the swivelling frame 2. One of the eccentric cranks indicated at T, is driven through a conventional electric motor (not shown in the drawing). It is closed by a cover plate 3, in which is an opening 5, through which pig iron from the furnace or furnaces 4a can be admitted. Discharge of metal from the ladle is through an outlet 15.

Cast iron, which may be continuously drawn off from each or either of the cupola furnaces 4a by means of a stationary tap or spout 4 flows into a Well portion 8, acting as collector, of anindependent spout or channel 7, from whence it passes through an orifice 6 into the shaking ladle 1.

To prevent temperature losses, the admission opening 5. of the cover in the normal or vertical position of the ladle 1 is covered in by a canopy-like radiation screen 16, which forms part of the spout 7. In order to accommodate the tipping rnovement of the ladle, which takes place in a circular path, the underside of canopy 16 conforms to the are of a circle whose centre coincides with the tipping axis of journals 12; likewise the upper surace of the cover plate 3 is of arcuate formation. In order to permit unhindered transfer of -pig iron from the furnace to the ladle, even when fully tipped as when filling a casting vessel, the opening 5 provided in the cover 3 of the ladle is so shaped and so adjusted as to length in relation to the outlet of the spout 7 that the orifice 6 registers with opening 5. In the tipped position (pouring position) of the ladle 1 the forward part of the admission opening 5 is exposed, so that on completion of the filling of one or more casting vessels it is possible to introduce additions and alloying media into the shaking ladle. The ladle is thereupon swung back into its vertical position (FIGURE 1) and during the further admission of iron the metallurgical shaking ladle treatment is carried out in known manner. When operating the plant in this manner it has been found advantageous, in order to avoid temperature losses in a dependable manner, to keep the shaking ladle always about half full of molten iron.

Should it be necessary to remove the slag which has accumulated in the shaking ladle 1, this can be effected by tipping the ladle in the reverse direction, i.e. backwards, towards the cupola furnace, and tapping off the slag without interrupting the flow of iron. By raising the front portion of the tapping spout 7 such as by means of a hydraulic ram 20, the admission of iron into the shaking ladle can be temporarily suspended, in which case the cupola furnace iron collects in the well portion 8 of the spout 7. The shaking ladle can then be tipped back through 180 after completely pouring out the iron, so that the slag falls out freely. The ladle is then swung back into the admission position and the spout portion 7 lowered, so that the molten iron present in the well 8- runs 01f into the shaking ladle. When the tapping spout 7 is raised, the shaking ladle can also be replaced, or even quickly repaired, without interrupting the melting and pouring operations.

We claim:

1. In a cupola furnace apparatus, the combination of a furnace having a tapping outlet through which molten metal from the furnace is continuously discharged, a ladle; a shaking ladle-means mounting the ladle so as to be capable of displacement from a normal to a tipping position, said ladle having a cover plate in which there is a supply opening for admission of molten metal, and

4 an outlet opening for pouring molten metal therefrom; a tapping spout, one end of which is located to receive metal from the tapping outlet of the furnace and in the other end of which is a discharge orifice for feeding metal into the ladle, the supply opening in the ladle extending over an arc whose length is proportional to the angular displacement of the ladle in moving to and from its tipped. position for charging metal into the ladle injall angular positions of the ladle, even when the ladle is-in a tapping position in which molten metal is being poured from said outlet opening thereof.

2. Apparatus as claimed in claim -1 comprising a tapping spout having a well at one end into which metal from the tapping outlet of the furnace is delivered.

3. Apparatus as claimed in claim 2 in which said cover plate has an arcuate cross section, and the tapping spout is provided at its discharge end with a canopy having an arcuate cross section corresponding to that of said cover plate, the discharge orifice for metal being formed in the canopy.

4. In a cupola furnace apparatus, the combination of two furnaces each having a tapping outlet from which molten metal is continuously discharged, a shaking ladle, means mounting said ladle so as to be capable of displacement from a normal to a tipping position, a tapping spout having at one end, a well into which metal from the tapping outlet of each furnace is discharged and provided at its other end with an orifice from which metal is fed to the ladle, a cover plate for the ladle, said cover plate having an outlet opening for pouring molten metal from said ladle, and a supply opening extending over an arc whose length is sufficient to accommodate angular displacement of the ladle in moving to and from its tipping position for charging metal from the tapping spout to the ladle in the normal position and in all angular positions of the ladle.

5. Apparatus according to claim 1, wherein said arcuate supply opening comprises a slot-like opening having a substantially circular opening at one end thereof. I

References Cited UNITED STATES PATENTS 667,131 1/1901 Illingworth 259-75.

670,279 3/1901 Illingworth 259- 2,227,255 12/1940 Gronwall 164-260 2,398,455 4/1946 Unger. 2,842,354- 7/19518 Hohne 266-13 X'R 3,251,681 4/1-966 Wa'kamatsu et a1. 259-91 X'R 3,259,485 7/ 1966 Kootz et al 25975 XR -3,31 1,361 3/1967 Zepernick 266-64- FOREIGN PATENTS 817,956 8/1959 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner. R. S. ANNEAR, Assistant Examiner. 

